Twenty people were killed on board a Russian nuclear submarine, the navy said on Sunday, in an accident that exposed the gap between the Kremlin's ambitions and its military capability.
The accident, which happened while the submarine was on sea trials in the Pacific Ocean, was the deadliest to hit Russia's navy since the Kursk nuclear submarine exploded beneath the Barents Sea in 2000, killing all 118 sailors on board.
Prosecutors investigating the latest incident said they suspected the victims died after inhaling a toxic gas used as a fire suppressant when the vessel's fire extinguishing systems went off unexpectedly.
It was not clear why the portable breathing gear usually issued to Russian submarine crews did not save them. A navy spokesman said the nuclear reactor was not damaged and the vessel was now in port.
"Twenty people died," the Prosecutor-General's Office said in a statement. "Results of a preliminary investigation show that death occurred as a result of freon gas entering the lungs."
Twenty-one people were injured and taken to a military hospital in Vladivostok. Many of those on board were civilian workers from the shipyard that built the submarine. Vera Sanzhonova said she had driven to Bolshoi Kamen, the naval base where the submarine was moored, to seek word on her husband, a civilian technician who was on board.
"I have not received any news. My husband is neither on the list of those injured nor among the dead," she told Reuters. "I've been driving here all the way down from Vladivostok, shedding tears and swallowing pills."